JPS63232321A - Alignment method - Google Patents

Abstract

PURPOSE:To improve accuracy of alignment, by measuring the amount of position shift in prescribed regions on a substrate by a TTL method and performing alignment of an original plate to the substrate in the respective regions on the substrate on the basis of correction lattice information formed from the results of measurement. CONSTITUTION:The amount of position shift of an original plate RT to a substrate WF in prescribed regions on the substrate WF is measured by observing light which transmits a projection optical system LN and is reflected on or diffracted from marks on the substrate WF (a TTL method), and theta directional alignment of the substrate WF is performed on the basis of the results of measurement. Thereafter, similarly the amount of position shift of the original plate RT to the substrate WF is measured again by the TTL method in the prescribed regions on the substrate WF. Next, correction lattice information is formed on the basis of the results of measurement and stored, and alignment of the original plate RT to the substrate WF in the respective regions on the substrate WF is performed on the basis of the correction lattice information. Hence, alignment of the original plate to the substrate can be performed with good accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an alignment method, for example, for aligning an original plate such as a mask or reticle and a substrate such as a semiconductor square with high accuracy in an exposure apparatus that is a semiconductor manufacturing device. alignment)
Regarding how to.

[Prior Art] In recent years, as semiconductor integrated circuits such as ICs and LSIs have become smaller and more highly integrated, semiconductor exposure apparatuses have become increasingly sophisticated. Particularly at present, it is required that the original plate and the substrate to be aligned be superimposed on the order of submicrons.

A device called a stepper is known as an exposure device used in such semiconductor manufacturing. This stepper is
While the substrate, such as a semiconductor wafer, is moved step by step under a projection lens, the pattern image formed on the original plate, such as a reticle, is reduced by the projection lens, and multiple locations on one wafer are sequentially exposed to light. .

Then, as one alignment method between the reticle and the wafer in the stepper, TTL (Through) is used to align the reticle and wafer through a projection lens.
gh The Lens) method. Furthermore, TTL
Two methods of alignment are: ■Die-pie-die alignment method, in which alignment is performed for each shot, and ■Alignment is performed based on the results at an appropriate number of measurement points, and then the wafer is stepped according to the shot arrangement. There is a global alignment that performs exposure and the like.

[Problems to be Solved by the Invention] However, in general, the TTL die-pie-die method performs alignment for each shot of the wafer, so although the overlay accuracy is high, the processing time for one wafer is lengthened. Overall throughput decreases. On the other hand, TTL global alignment reduces the processing time for one query, but has the problem of poor overlay accuracy for each shot.

SUMMARY OF THE INVENTION In view of the problems with the conventional method described above, it is an object of the present invention to provide an alignment method with extremely high alignment accuracy and high productivity (high speed).

[Means and effects for solving the problem] In order to achieve the above object, the alignment method according to the present invention first calculates the amount of positional deviation between the original plate and the substrate in a predetermined area on the substrate using a projection optical system. Then, based on the measurement results, the substrate is aligned in the θ direction, and then the amount of positional deviation between the original plate and the substrate is similarly measured in a predetermined area on the substrate using TTL, Based on the measurement results, corrected grid information is created and stored, and the original plate and the substrate are aligned in each area on the substrate based on the corrected grid information.

Measuring the amount of positional deviation using the TTL method is a measurement by observing reflected or diffracted light from a mark on the substrate that passes through the projection optical system. Further, the corrected grid information is information including coordinates and the like indicating the position of each area arranged on the substrate. In particular, it does not have to be coordinate information, and may be expressed by, for example, the amount of step movement of the substrate from one area to the next area.

In addition to aligning the substrate in the θ direction, the original plate and the substrate should be aligned in the θ direction so that the amount of θ direction deviation in each area is minimized on average based on the amount of θ direction deviation in the measured area. Then, the θ correction for each area will be performed, and more accurate alignment will be possible.

In addition, if an offset is input to the correction grid information from the outside, and the position is forcibly shifted by the offset amount from the position of the correction grid, then
This is convenient because it can deal with regular errors that inevitably occur during alignment.

[Example] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a schematic diagram of a semiconductor exposure apparatus to which an alignment method according to an embodiment of the present invention is applied.

In the same figure, ST is an XY stage that moves the quest in the X and Y directions, and XM and YM are
, a drive motor that drives in the Y direction, WS a θ stage that rotates the wafer in the θ direction, WF the wafer, and OA an off-axis microscope that detects pre-alignment marks and performs rough alignment. In addition, LN is a printed projection lens, R3 is a reticle stage that moves the reticle in the X, Y, and θ directions, RT is the reticle, and PT is the reticle R.
The circuit pattern drawn at T and LI is a lighting device for printing. LT is a laser tube, PM is a polygon mirror, M
is a motor that rotates the polygon mirror, Pl is a prism that divides the optical path of the laser beam, and P2. P3 is a mirror,
BSI and BS2 are beam splitters, Ll and L2 are objective lenses, MR and ML are mirrors, DR and DL are photoelectric detectors, CB is a control box equipped with a control circuit consisting of a CPU (central processing unit) and memory, etc. This is a console that allows you to input various parameters.

In the figure, the laser beam emitted from the laser tube LT is directed to a polygon mirror PM rotated by a motor M.
It is then divided into a left visual field system and a right visual field system by a prism P1. The divided laser beams are transmitted through beam splitters BSI and BS2, objective lenses Ll and L2, and mirror MR.
, ML, and scan the alignment mark on the reticle and the alignment mark on the wafer, respectively. The reflected light from each mark returns to the optical path it came from, beam splitter BSI, ! It passes through 3S2 and enters photoelectric detectors DR and DL. Photoelectric detector DR, DL
photoelectrically converts this incident light and outputs it as an electrical signal. This output is input to the control box CB and is binarized, and the relative position of each mark (11 to ILs in FIG. 2(d)) is calculated from this binarized signal. From the above, the amount of deviation between the reticle RT and the wafer WF can be determined.

Figure 2 (a) shows the alignment mark W attached to the
1. FIG. 2(b) shows an alignment mark M attached to the reticle, and FIG. 2(C) shows a state in which alignment is completed. FIG. 2(d) is a diagram showing how the alignment mark M on the reticle and the alignment mark W on the wafer are scanned with a laser beam. FIG. 3 is a diagram showing the arrangement of alignment marks in each exposure area S (shot area) on the wafer. Alignment marks W1 and W2 are arranged for each shot area.

In this embodiment, as shown in FIG. 2(d) (specifically, as explained in FIG. 1 above), the alignment marks W and M are scanned by the laser beam L, and the relative path between each mark is 11
Find x, ~i5°, and find.

These ΔX and ΔY are determined for each of the alignment marks (FIG. 3) attached to both sides of the shot area.

For example, ΔYIL of Δx1 is obtained by measuring the left mark of shot 1, and ΔYIL is obtained by measuring the right mark.
If XIR+ΔY IRL is obtained, the amount of deviation of that shot in the X, Y, and θ directions can be determined, for example, as follows.

However, L indicates the distance between the left and right marks. The amount of deviation in the θ direction is a so-called tip rotation.

In this embodiment, several predetermined shots are predetermined automatically or specified by the user, and the chip rotation in the shot area is determined and averaged.
θ correction is performed in the shot area. In addition, the center position of a predetermined shot is determined using the above-mentioned formula for the amount of shift in the Y direction, and the difference between the center positions of the left and right shots is determined, and the wafer rotation is determined from this.

FIG. 4 is a diagram showing a shot layout on a wafer.

Next, the operation of the apparatus of this embodiment will be explained in detail with reference to the flowchart of FIG.

First, an overview of the processing will be explained.

Steps 1 and 2> These are the Unihachi set and TV pre-alignment.

Steps 3 to 9> The amount of deviation is measured in a predetermined shot area on the wafer, the amount of deviation in the θ direction is calculated from the measurement result, and the rotational component is corrected by driving in θ. Furthermore, the measurement is performed again to confirm that the θ correction is appropriate. Through steps 3 to 9, the position of the wafer in the θ direction is guaranteed.

Steps 10 to 19> The amount of deviation is measured in a predetermined shot area on the wafer, and based on the results, a correction grid, that is, information including coordinates indicating the position of each shot area, is created. If a correction grid is created and stored, alignment with a predetermined accuracy is guaranteed by alignment using the correction grid points.

Note that when wafers coated with resist are aligned and baked, the baked results may be radially, spirally, or randomly shifted. Since such misalignment does not occur on wafers to which no resist is applied, it is thought that the resist application is the cause. In this embodiment, in order to deal with this, an offset is input from the console in advance, and when creating a correction grid, the above-mentioned offset amount is added to calculate the correction grid. Therefore, during the 11 position alignment, the stage is driven with the offset added. This makes it possible to prevent regular misalignment among the above-mentioned unavoidable misalignments.

Next, the operation of the apparatus of this embodiment will be explained in detail.

First, in step 1, wafer WF is placed on wafer stage WS. Next, in step 2, the off-axis microscope f
Perform TV pre-alignment using iOA. This allows rough alignment of the wafer WF.

The next step 3 to step 9 is a loop for performing θ correction in positional deviation measurement. First, in step 3, the amount of deviation is measured at TTL' for the L shot (the shot shown in black) in FIG. 4. This measurement is performed as explained in FIGS. 2 and 3 above. Also,
The position of the measurement shot is automatically selected according to a predetermined rule as described later, but it can also be changed by giving an instruction from the console CON.゛Next, in Step 4, it is determined whether the above measurement was good or not. If it is bad, in Step 4a, the XY stage is stepped to the adjacent shot, and the process returns to Step 3 again to measure the amount of deviation in that shot. . In the case of poor measurement, adjacent shots are automatically selected according to predetermined rules. Further, here, the number of steps to adjacent shots is limited to two shots.

If the measurement is good in step 4, proceed to step 5 and λ
It is determined whether or not measurement has been completed for all shots, and if it has not been completed yet, the process advances to step 5a to proceed to the next shot to be measured, and then returns to step 3 to perform measurement. Note that the number l is selected in advance from the console. However, it is assumed that the shot is selected from m shots, which will be described later, and λ≦m.

If it is determined in step 5 that the measurements for all °C shots have been completed, the process proceeds to step 6 to determine whether there is an abnormal shot. Here, when the maximum deviation of pitch error and chip rotation is larger than a predetermined value, it is considered an abnormal value. In the case of an abnormal value, the abnormal value is rejected, step is performed to an adjacent shot in step 6a, and measurement is performed again from step 3. As with step 4a, up to two adjacent shots are automatically selected. If there is no abnormality in step 6, it is determined in step 7 whether the number of effective shots is greater than or equal to the minimum number of shots. The minimum number of shots is set, for example, as follows, corresponding to the number of measurement shots β.

If the number of effective shots is smaller than this minimum value, the process proceeds to step 7a. In step 7a, it is determined whether the mode is automatic measurement, and if so, the process returns to step 3 and re-measurement is performed. That is, when the number of abnormal value rejects is abnormally large, re-measurement is performed in automatic fishing. If it is not the re-measurement mode, the process proceeds to step 7b and an error occurs. In the event of an error, the device is temporarily stopped, and then the operator is informed through the console whether to continue, reload, or try again, and processes are performed according to the instructions.

Next, in step 8, chip rotation, wafer rotation, shift amounts in the X and Y directions, etc. are measured, and abnormal values are rejected. This abnormal value reject is performed when the residual deviation amount r/σ is larger than a predetermined value.

If the number of abnormal value rejects is greater than a predetermined value, the process branches to step 7a and the aforementioned process is performed.

Next, in step 9, it is determined whether the amounts of wafer rotation and chip rotation are within a predetermined tolerance. If not within tolerance, step 9a
and the reticle θ stage (hereinafter referred to as reticle θ/S)
After correcting and driving the 〇 stage (hereinafter referred to as wafer θ/S) and the XY stage (for shifting), the process returns to step 3 for re-measurement of one shot. Note that since remeasurement is limited to two times here, the determination in step 9 will be performed three times. In addition, since the loop processing of steps 3 to 9 is repeated in the re-measurement, the tolerance value is slightly increased in the third re-measurement, and the conditions for discrimination are relaxed.

This tolerance value can be changed by user input.

If it is within tolerance in step 9, step 1
The process proceeds to the θXY correction loop of positional deviation measurement from step 0 to step 18. In this θXY correction loop, θ correction, magnification correction, and shift correction of the wafer are performed by driving the XY stage. We also obtain various measurement values for creating a correction grid.

First, in step 10, TT for the m shot in FIG.
The amount of deviation is measured at L. This measurement is performed in the same manner as the one shot described above. Further, the position of the measurement shot is automatically selected like the one shot, but it can also be changed by giving an instruction from the console CON.

Next, in step 11, it is determined whether the above measurement is good or not. If it is bad, in step 11af, the XY stage is stepped to an adjacent shot, and the process returns to step 10 again to measure the amount of deviation in that shot. In the case of a measurement failure, adjacent scissors are automatically selected according to predetermined rules. Further, here, the number of steps to adjacent shots is limited to two shots.

If the measurement is good in step 11, the process proceeds to step 12, and it is determined whether or not the measurement has been completed for all m shots.If the measurement has not been completed yet, the process proceeds to step 12a, where the process moves to the next shot to be measured, and then steps again. 10
Go back and take measurements. Note that the number m is selected in advance from the console. For example, the value of m is selected from m=2.4, 6, 8, 12.16, etc. Note that the one shot mentioned above is selected from m shots and used in the θ correction loop. Therefore, in steps 3 to 9, θ by one shot is
When the measurement in step 10 is performed for the first time after performing the correction loop, the measurement is performed by excluding two shots from among the m shots (only the mouth in FIG. 4). From the second loop, all m shots (the cabinet and mouth in Figure 4) are subject to measurement.

Returning to the sequence description, in step 12 all m
If it is determined that the measurement for the shot (excluding the shot in the first loop) has been completed, proceed to step 13.
to determine whether there are any abnormal shots. Here, the same check as in step 6 is performed, and if an abnormality is found, step is performed to an adjacent shot in step 13a, and measurement is performed again from step 10. Selection of adjacent shots is similar to steps 4a and 6a. If there is no abnormality in step 13, it is determined in step 14 whether the number of effective shots is greater than or equal to the minimum number of shots. As in the case of shot 1, a predetermined value is determined for the minimum number of shots in correspondence with the number m of measured shots. If the number of effective shots is smaller than this minimum value, an error is determined in step I4a, and the same processing as in step 7b is performed.

Next, if the number of effective shots is greater than or equal to the minimum number of shots in step 14, chip rotation is performed in step 15.
Wafer rotation, shift amount in the X and Y directions, and magnification are calculated, and abnormal values are rejected. This abnormal value reject is performed when the residual deviation amount r/a is larger than a predetermined value. Note that if there are an abnormally large number of abnormal value rejects in steps 14 and 15, automatic re-measurement may be performed in the same manner as in step 7a.

In this case, the process returns to step 10.

Next, in step 16, it is determined whether each component is within a specified range. That is, for chip rotation, wafer rotation, magnification, and arrangement, it is determined whether each component is a dog based on user-set values. If it is large, it is assumed that an error has occurred and the operation is stopped in step 16a. The processing at this time is similar to step 7b.

If each component is within the specified range in step 16, in step 17 the console selects whether or not correction driving is necessary. If correction driving is to be performed, it is determined in step 18 whether the rotation (wafer 0), shift (XY), and magnification are within tolerance. This tolerance value is entered from the console. Remeasurements may be made up to two times. Therefore, the determination in step 18 can be made up to three times. Step 1
If it is out of tolerance in step 18a,
The Y stage is driven for correction, and the process returns to step 10 to perform measurement.

Furthermore, if it is within the tolerance in step 18, a correction grid is created in step 19. Even if it is not necessary to confirm the correction drive in step 17, the process branches to step E9 and a correction grating is immediately created.

Thereafter, the exposure sequence from step 20 is executed. First, in step 20, a selection is made between global alignment and die-pie-die alignment. This selection is made by inputting from the console.

In the case of global alignment, the XY stage is moved in steps to expose the first shot area in step 21, focusing and exposure are performed in step z2, and it is determined in step 23 whether or not it is the final shot. If it is not the final shot, the process advances to step 23a to proceed to the next shot, and returns to step 22 to perform focusing and exposure. This is repeated, and when the final shot is reached, the wafer is reloaded in step 31, and processing proceeds to the next wafer.

On the other hand, in the case of die-pie-die alignment, in step 24 the XY stage is moved step by step to expose the first shot area, and in step 25 the amount of deviation of the shot is measured by TTL.

Next, in step 26, it is determined whether the amount of deviation is within the limit. The limit value is input in advance from the console CON. If this limit value is exceeded, the reticle is centered in step 30, and the process proceeds to step 28, where focusing and exposure are performed at the correction grid points. If it is within the limit, it is determined in step 27 whether the deviation amount is within the tolerance.

If the tolerance is out of step 27, the reticle XY stage is driven in step 27a, and the process returns to step 25.

On the other hand, if it is within the tolerance in step 27, focusing and exposure are performed in step 28. After exposure, it is determined in step 29 whether or not it is the final shot. If it is not the final shot, step 29a advances to the next shot, and the process returns to step 25. When the exposure of the final shot is completed, the wafer is loaded in step 31, and the process proceeds to the next wafer.

According to the global alignment described above, when moving stepwise to each shot area, the chip θ and wafer θ are corrected in advance by a θ correction loop, and a correction grid is created based on measurement results in several shot areas. Since positioning is performed according to the data, a certain level of accuracy is always guaranteed. Furthermore, since the stage is moved eight times in accordance with the pre-stored data of the correction grid, the speed is high and the throughput of the apparatus is high.

Furthermore, according to the die-pi-dia alignment described above, after performing θ correction and creating a correction grating,
Performing pi di-alignment. Therefore, since alignment has already been done in the θ direction, there is no need to look at it, and alignment only needs to be done in the X and Y directions, so alignment can be performed faster than normal die-pie-die alignment. In addition, since a correction grid has been created, the amount of movement during alignment is smaller than normal die-pie-dia alignment, and if an abnormal value is detected, a certain level of accuracy can be achieved by aligning according to the correction grid. Guaranteed.

In this embodiment, not only the wafer 〇 but also the chip θ are measured and averaged for alignment. This is particularly effective when the alignment mark is not placed off-center, that is, at a position where the straight line connecting the center of the chip and the mark is parallel to the X or Y direction. In other words, if the chip is off-center or measured with a single mark, the chip center position calculated based on the measurement results may shift, and this error will affect the correction value for wafer 〇, resulting in the correction. This is because the accuracy of the grid deteriorates.

In addition, in this example, a predetermined shot area is measured using the TTL method instead of off-axis, so that the error between the running direction of the XY stage and the off-axis microscope becomes an error in the correction grid, as in off-axis. Never happened.

Switching between global alignment and die-pie-die alignment can be performed automatically or can be specified manually. If this is done automatically, for example, it can be determined by the number of shots rejected due to measurement abnormalities, or by the dispersion of measurement values ((difference in m). If there are many abnormal shots or deviations, use global alignment to average the position. However, if the number is small, it is better to use die-pie-die for more accurate alignment.

In this embodiment, after performing the θ correction, the process returns to the beginning and remeasures one shot. By performing such correction confirmation, the position end 1i(7)θ correction can be performed more effectively, and subsequent measurements can be processed satisfactorily.

Furthermore, in order to improve accuracy, various methods can be considered for rejecting abnormal values of measured values. For example, it is preferable to make a comparison with a predetermined absolute value, to make a judgment based on the variance of the measured data value (for example, 3σ), or to make a judgment by a combination of these. Also, if there are an abnormally large number of abnormal value rejections, it is a good idea to automatically re-measure.

In this embodiment, the wafer θ is corrected by the wafer θ/S, and the chip θ is corrected by the reticle θ/S.

Therefore, highly accurate θ positioning is possible.

Next, a basic algorithm for selecting m shots, which are sample shots, will be explained.

First, the index Ind (n) of shot n is defined as the smallest number among the four shot numbers counted from shot n up, down, left and right to the outermost circumference.

For example, Ind(n)=1 in FIG. 6(a).

The set of shots whose index is k is written as Ib.

Also, when the number of elements of Ik is a, ■.

Write =a. In FIG. 6(b), ◎ is all elements of I, and l1=18. Note that the index of the outermost shot is 0.

In addition, it is defined as follows.

(1) The given shot arrangement is ■. , I1°I2.・
. . . is composed of indices up to Ik.

(2) T is the total number of sheets, T = Io + I,
＋・・・・・・＋■5.

(3) S is global alignment or die-pie
This is the number of sample shots selected for die alignment.

(4) Pn is when p,'= (xn, 3'n), where Pn' is a vector extending from the center of the shot array (not necessarily the shot center) to shot n.

(5) el is a unit vector i=1.2 extending in each direction from the center of the shot array when 360° is divided into S equal parts.
......, S.

Next, general rules for selecting sample shots m to be measured will be explained.

■ First, focus on 11. If 11≧S, divide 360° into S equal parts and get '91+ e2・
...Make e3.

Next, for each e, (i=1 to S), the inner product e+Pj (
i −1 to S, j = I r ), and j that gives the maximum value is taken as a sample shot.

■ Calculation of the inner product is performed counterclockwise until a certain eI
If there are multiple shots that give the same inner product, the most counterclockwise shot is taken as the sample shot.

■ If the same Pn is selected for multiple eIs, only the sample shot for the first eI calculated (i.e. the el closest to the clock) is adopted, and other eIs are
The sample shot for I is put on hold and the inner product calculation continues. This is to prevent double selection.

■ If I r < S, then 1. are all sample shots, and the remaining S-I and S-I are selected from I2. That is, S is replaced with I, -3, 11 is replaced with I2, and the processing from (2) is performed.

■ Perform the above calculation as 11→I2→I o = I 3→・
...Continue up to Ik.

However, shots where the distance from the center of the shot array to the shot center is 20 mm or less are excluded.

■ The sum of the number of one-eye shots and the elements of an index set with 4 or less elements: +T'.

If T-T'<S, there are too many S, so the process is stopped as an error.

Next, selection of sample shot m in global alignment will be explained in more detail.

That is, sample shots are selected under the following conditions.

■ Exclude the outermost circumference to avoid abnormal offset check values. This is because the measurement accuracy is poor at the outermost circumference. Note that the offset check value is the amount of deviation of each shot in the X, Y, and θ directions calculated based on the measured values of the sample shots.

■ Translational (XY direction) components (sx, sy).

Rotation (θ direction) component (ex, ey).

The precision (dispersion) of each expansion/contraction rate (β8.βy) should be approximately equal.

V (SX > = O (SF > v (e,
) 甔v(ey) ■ (βx ) '9 V (βy)■ Under the following conditions, the overall variance is made as small as possible.

That is, W=V (S) +V (e) +V (β) is minimized.

From the conditions of ■ and ■, the i-th shot coordinates are (X+,
y+), it is sufficient to set Σx1=ΣV1=ΣxlyI=0 Σx12=Σy12. Therefore, it is best to select an arrangement that is symmetrical with respect to the origin and retains its shape even when rotated by 90 degrees from among shots that are as far away from the origin as possible.

This shows that it is better to select a shot area that is point symmetrical with respect to the center, excluding the center area of the wafer, for the measurement shot. This is because if there is point symmetry, the center position can be calculated with high accuracy.

■ Consider stage accuracy and cross-correlation of offset check values, and create shot arrays that are as spatially dispersed as possible.

■ Even if there is a poorly measured shot or an abnormal shot,
Make sure there is no significant deterioration in accuracy.

By automatically selecting sample shots under the above conditions, an averaged deviation 1 measurement value can be obtained, and the accuracy in the θ correction in steps 3 to 9 in Fig. 5 described above and the value created in steps 10 to 19 can be obtained. The accuracy of the correction grid is guaranteed. In addition, since everything is automatically selected, there is no reduction in throughput. Roughly speaking, even when re-measuring with a substitute shot because the measurement in a certain shot was abnormal, it is convenient because it can be automatically selected in the same way as above.

[Effects of the Invention] As explained above, according to the present invention, the substrate is first aligned in the θ direction at T'TL in a predetermined region on the substrate, and then aligned in the TTL in a predetermined region on the substrate. The amount of positional deviation is measured, correction grid information is created based on the measurement results, and the alignment between the original plate and the substrate in each area on the board is performed based on the correction grid information. Positioning can be performed with high alignment accuracy and high productivity (high speed).

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a semiconductor exposure apparatus to which an alignment method according to an embodiment of the present invention is applied, and FIG. 2 is a diagram showing an alignment mark and how the alignment mark is scanned with a laser beam. , FIG. 3 is a diagram showing the arrangement of alignment marks in each exposure area on the wafer, FIG. 4 is a diagram showing the shot layout on the wafer, and FIG. 5 is for explaining the operation of the apparatus of the above embodiment. FIG. 6 is a schematic diagram for explaining the sample shot selection algorithm. ST: stage, XM, YM: drive motor, WS: θ stage, WF: wafer, oA: off-axis microscope, LN: printing projection lens, RS doubleticle stage, RT doubleticle, PT dual circuit pattern, LT: printing lighting Equipment, LT: Laser tube, PM: Polygon mirror, M: Motor, P1 Nibrism, BSI, BS2: Beam splitter, DR, DL: Photoelectric detector, CB: Control box, CON: Console. Patent Applicant Canon Co., Ltd. Agent Patent Attorney Tatsuo Ito Agent Patent Attorney Satoshi Ito Ikino 1 Figure (b) / II6 figure procedural amendment (voluntary) June 23, 1986

Claims (1)

[Claims] 1. Prior to sequentially projecting the pattern drawn on the original onto a plurality of areas arranged on the substrate via a projection optical system, the above-mentioned A first measurement is performed to determine the amount of misalignment between the original plate and the substrate in a predetermined area on the substrate, and the substrate is aligned in the θ direction based on the first measurement result. perform a second measurement to determine the amount of positional deviation between the original plate and the substrate in a predetermined region of the substrate using the TTL method, create and store correction grid information based on the second measurement result, and store the correction grid information in the correction grid information. An alignment method characterized in that the original plate and the substrate are aligned in each of the areas based on the above. 2. Calculate the amount of deviation in the θ direction of each region from the first measurement result, and align the substrate in the θ direction, and also determine the minimum amount of deviation in the θ direction of each region on average based on the calculation results. 2. The alignment method according to claim 1, wherein the original plate and the substrate are aligned in the θ direction so that the following is achieved. 3. The alignment method according to claim 1 or 2, wherein an offset for the corrected grid information can be input.